popular
    .panel.panel-default
        .panel-heading
            h3.panel-title 最受欢迎
        .panel-body
            each pop in popular
                .col-md-4.text-center(style='padding-bottom: .5em;')
                    a(href=`/images/${pop._id}`)
                        img.img-thumbnail(src=`/upload/${pop.filename}`, style='width: 75px; height: 75px;')
